Quantitative Contributions of the Sources, Contamination and Ecological Risk of Heavy Metals in Soils from a Closed Coal Mine of Huaibei Coalfield, Eastern China.

With the increasing number of closed mines, the geological environment problems around closed mines have become increasingly prominent, especially in terms of soil pollution. In this paper, a total of 32 topsoil samples were collected from Qianling closed coal mine and the contents of Cu, Zn, Co, Cr, Mn, As, Cd and Pb were analyzed. The results indicated that the contents Zn and As exceeded the surface soil background values of Anhui Province. Compared with the soil of production mines, the contents of Pb and Zn were higher. The assessment results of pollution and ecological risk of soil based on Nemerow index, Geological accumulation index and potential ecological risk assessment method showed that the closed coal mine was in the mild to moderate pollution and mild hazard ecological risk. The Pearson correlation and positive matrix decomposition model were applied to identify the sources of soil heavy metals, which included atmospheric dustfall (22.47%), natural factors (22.51%), agricultural activities (4.40%), transportation (8.90%) and industrial emissions (42.08%), respectively. [ABSTRACT FROM AUTHOR]